管路阻力 meaning in English

pipe resistance

Points out that some designers only use empirical methods in determining the inner diameter of pipeline , calculating system resistance and selecting the rated flow and rated head of circulating pumps in water systems
摘要指出目前一些设计人员在设计空调水系统时，仅根据经验值估算管道内径、计算管路阻力和选配系统循环水泵的流量和扬程。
It is indicated that , when a two - speed motor is used for driving oil transfer pump , the motor with the characteristic of torque reduction on square rotary speed should be chosen ; the working economy of the variable speed pump is restricted by the characteristic curves of pipeline resistance , and its speed control range is restricted by the pipeline resistance characteristic curve , the pressure head needed by the system and the working characteristic of the pump ; when several pumps work in parallel , the pump with better performance should be changed into speed - variable pump
指出双速电动机用于输油泵的调速时，应选用转矩按转速平方降低特性的电动机；调速泵的运行经济性受到管路阻力特性曲线的限制，其调速范围受到管路阻力特性曲线、系统所需扬程和泵运行特性的限制；在母管制系统中把部分定速泵改为调速泵时，应将性能较高的定速泵改为调速泵。